Lisnasari, Srie Faizah, et al. “The Importance of Principal Leadership Management in Increasing the Competence of Elementary School Teachers in Medan City, North Sumatra ”. International Journal of Multidisciplinary: Applied Business and Education Research, vol. 4, no. 2, Feb. 2023, pp. 609-15, https://doi.org/10.11594/ijmaber.04.02.27.